yesterday morning. dorner allegedly opens fire on police officers in corona and riverside, california, killing one and critically injuring another. police put out on the word to be on the lookout for a blue or gray nissan pickup truck, the model of car dorner was known to be driving. late thursday morning came word of a burned-out truck in big bear, california. it's dorner's car. the massive manhunt moves to the mountains of big bear, on foot and by air. schools in the ski resort shut down as dozens of police combed the wooded area for any sign of dorner. several hours of snow made conditions difficult and grounded the air search. now today u.s. marshals and the irvin police department executed a search warrant at the house of dorner's mother. they say it's his last known residence. police questioned dorner's mom and sister and removed several bags of evidence, including a laptop computer. and the manhunt, while focused on big bear, has now spread to